1. Field of the Invention
The invention relates generally to handheld electronic devices and, more particularly, to a keypad for a handheld electronic device.
2. Background Information
Numerous types of handheld electronic devices are known. Examples of such handheld electronic devices include, for instance, personal data assistants (PDAs), handheld computers, two-way pagers, cellular telephones, and the like. Such handheld electronic devices are generally intended to be portable and thus must be relatively small. Many handheld electronic devices feature wireless communication capability, although many such handheld electronic devices are stand-alone devices. Since handheld electronic devices typically are portable, it is also desired that the form factor of the devices be sufficiently small and ergonomic that they can conveniently be transported with a belt clip, in a user's pocket, manually, or in a briefcase. Advancements in technology have permitted the form factor of such handheld electronic devices to be reduced while increasing their versatility and functionality, such as by increasing the number of functions provided by the device as well as increasing the number of software applications and the variety of their features. However, as the form factor of a handheld electronic device decreases and the number of functions provided by the device increases, the device potentially can become awkward and difficult to use. Thus, it is also desirable to improve the usability of a handheld electronic device as its form factor is reduced and its versatility is increased. Previous attempts to increase such usability have had limitations.
One such type of solution has involved the use of large numbers of keys which, when pressed in various combinations, would produce various functions. For instance, adjacent keys were depressed simultaneously to provide additional functions. In mobile electronics, keys oftentimes are operatively connected with metal or carbon coated poly domes that act as switches for the keys and that are elastically collapsible and provide tactile feedback to a user when the domes are collapsed from a relaxed position to a deflected position. The simultaneous pressing of multiple keys to provide a given function thus oftentimes can result in the collapsing of multiple domes, which can result in a confusing and/or undesirable tactile feedback to a user. Other attempts at improving usability have involved decreasing the quantity of keys on a handheld device while increasing the number of functions each key is to serve. Such systems potentially can become cumbersome because the various functions of a given key may additionally require the pressing of a SHIFT key, an ALT key, or another key to provide the various functions. In such a circumstance, the required multiple key pushing requires multiple hand movements which can interfere with user friendliness.